Airbag Light: Why is It On? – The Common Reasons

modern car dashboard with indicators like airbag light

Today’s vehicles have more features than ever before. With the ever-growing technology in the automotive industry, most of these systems are controlled electronically. Gone are the days when there were just three or four warning lights on our driver’s display. There are indicators for everything from a loose gas cap to low washer fluid. With so many alerts on the display, it can be tempting to ignore them and keep on driving. However, when it comes to the airbag light, we cannot stress how important it is to deal with it.

What Is a Car Airbag Light?

deployed airbags

Image from Pixabay

The vehicle airbag light is the primary indicator for the Supplemental Restraint System or SRS. It is usually displayed with the SRS letters or an illustration of a person sitting in a car seat with the airbag deploying. As with all indicator lights, it comes on for a few moments every time the vehicle is started. This happens so the computer can check the system and make sure everything is in working order. If the light stays on though, it means there is something going on with the SRS system that needs to be looked into further.

How Does the Airbag Light Work?

Most vehicles display a written warning, such as “Air Bag,” “Air bag off” or “Air bag deactivated!” All of these warning lights are a part of the vehicle’s integrated safety system, which includes the seat belt and air bag systems. When there is an issue with anything concerning the SRS, an icon on the driver’s display panel will either light up or flash, indicating that the problem needs to be checked out immediately.

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How Does the Airbag System Work?

To better understand the importance of the airbag light and how urgent it is to have it diagnosed quickly, we will take a moment to explain exactly how the airbag system operates. It is made up of a network of sensors located throughout the vehicle, a computer module which processes the data sent from those sensors, and of course, the airbags themselves. The airbags are inflated or ‘deployed’ by a small charge initiated by the computer when it senses something that indicates a likely collision, such as sudden deceleration or impact.

Is It Safe to Drive with the Airbag Light On?

When the airbag light is on, you don’t know if it is just a sensor error or a more serious issue. The most important thing to consider is that even if there is nothing wrong with the airbags or the system which controls it, there is still something wrong with the way the computer is processing the data it receives. This means in a worst-case scenario, the airbags may not deploy in an accident. No matter how busy you are, that is just not a risk worth taking.

What Is the Purpose of the Car Airbag Light?

airbag light and fuel gauge

Image by Jellidonut from Pixabay

The primary function of the airbag light is to let the driver know there is some kind of issue with the airbag system. This could be any number of things from an electrical problem to a sensor issue, to airbags that have been deployed previously and not properly reset. In this section, we will take a deeper look into a few possible causes of the airbag light being on.

Seat Belt Sensor

This is an issue that occurs when something is interfering with the sensor and keeps the computer from registering that the seat belt is indeed fastened. Sometimes this can be something stuck down in the buckle like a coin or a small piece of metal. Other causes can be a blown fuse or even an electrical issue that may need to be diagnosed with a code.

Low Car Battery

When a vehicle’s battery has recently gone dead or been drained very low, the airbag’s backup battery is also drained, and this can cause the warning light to come on. Sometimes charging the car battery or replacing it with a new one will reset the light and it will turn off. If this is not the case, again, you need to have it looked at by a qualified professional.

Damaged or Broken Clock Spring

The clock spring is a rotary electrical connector located in the steering wheel that maintains the continuity of the vehicle’s electrical system, airbag system, and horn. One sure indicator that this is the problem is if, in addition to the airbag light being on, the horn is also not working.

Water or Flood Damage

A common location for the airbag module is under the driver’s seat. With this being the case, even a small amount of water or flood damage could corrode or short out the sensors, leading to an error code being sent to the main computer. Even spilling a drink in the wrong place can have this affect. Also, since it’s common for people to shove things under their seats, it is also possible that a connection could be damaged resulting in the same sensor error.

Sensor or Code Error

Sometimes electrical parts and components just wear out over time. There may be nothing you have done or anything else that caused an issue with your airbag system, it could just be that something went bad in the sensors or computer itself. If this is the case, a quick diagnostic from your local mechanic should identify the problem and it should be an easy fix.

What Should I Do If the Airbag Light Is On in My Car?

Our first suggestion would be that you take your vehicle to a certified mechanic as soon as possible. This could be any certified local auto repair shop or the dealership. We strongly recommend that you do not continue driving the vehicle as if nothing is wrong. The fact that the airbag light is on indicates there is an issue that needs to be addressed immediately as the airbags may not deploy in the event of an accident. For those who prefer to work on their cars themselves, here are a few troubleshooting options you can try:

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Replace the Clock Spring

As we mentioned before, the clock spring is what maintains the connection between the vehicle’s electrical and airbag systems. It does this by coiling in and out as the steering wheel turns. After years of use and tens of thousands of wheel rotations, the thin circuit bands may become brittle and worn, causing an intermittent connection, or eventually even no connection at all. This is common problem in older vehicles.

Charge or Replace the Battery

As batteries wear down, sometimes they hang on a while before going completely dead. Running the car or driving it will recharge it enough to where it continues to function adequately until it finally goes dead. If this is the case, it may have already caused an issue with the airbag sensor, and until you replace the battery, the airbag light will probably continue to stay on.

Check the Passenger Occupancy Sensor

Another possible cause for the airbag warning light may be the wiring or connection of the passenger occupancy sensor. Given how passenger seats are usually adjusted more often than driver’s seats, the back-and-forth repetition over time can stretch or fray the wires, and sometimes they can get detached altogether.

To check if this system is working properly, look for the “passenger airbag off” light when the seat is unoccupied, and look for that light to disappear when the seat is occupied. If the indicator is not functioning properly, check the harness and wiring under the seat for possible damage. If you do find an issue with the wiring, universal replacement kits can be purchased at nearly any auto parts store.

Clear the ECU

If you have throughly inspected every possible cause for the airbag light to be on and have concluded that there are no issues that need resolving, you can remove the airbag electronic control unit, or ECU, and send it to a company that will clear it for you. Still, we highly recommend letting a qualified mechanic give your system the once-over before taking this step, because this is something you want to make absolutely sure you are not wrong about. It may save your life.


Vehicles are getting more technologically advanced every year. We already have cars that can self-parallel park, brake on their own when sensing an impending collision, and warn us when other vehicles or objects are getting too close. Technology can make our drive so much more easy and comfortable, but only if we pay attention to it. Ignoring important indicators such as “check engine” and “low tire pressure” are surely dangerous enough. But when you ignore your airbag lights, you are literally playing Russian roulette with your life and the lives of the passengers traveling with you.

So please, don’t wait. Have your car checked out by your local mechanic today. We hope you will never need those airbags, but if you do, you will be glad they were there.